dataframe.count() to list code example

Example 1: pandas count rows with value

len(df[df['score'] == 1.0])

Example 2: pandas count number of rows with value

In [37]:
df = pd.DataFrame({'a':list('abssbab')})
df.groupby('a').count()

Out[37]:

   a
a   
a  2
b  3
s  2

[3 rows x 1 columns]

Example 3: pandas count

>>> df.set_index(["Person", "Single"]).count(level="Person")
        Age
Person
John      2
Lewis     1
Myla      1